The only metric that tracks how much nature we have – and how much nature we useEcological Footprint accounting, first introduced in the 1990s and continuously developed, continues to be the only metric that compares overall human demand on nature with what our planet can renew — its biocapacity — and distils this into one number: how many Earths we use.Our economy is running a Bernie Madoff-style Ponzi scheme with the planet. We use future resources to run...